DOKK / manpages / debian 12 / ndctl / cxl-free-dpa.1.en
CXL-FREE-DPA(1) cxl Manual CXL-FREE-DPA(1)

cxl-free-dpa - release device-physical address space

cxl free-dpa <mem0> [<mem1>..<memN>] [<options>]

The CXL region provisioning process proceeds in multiple steps. One of the steps is identifying and reserving the DPA span that each member of the interleave-set (region) contributes in advance of attaching that allocation to a region. For development, test, and debug purposes this command is a helper to find the last allocated decoder on a device and zero-out / free its DPA allocation.

<memory device(s)>

A memX device name, or a memdev id number. Restrict the operation to the specified memdev(s). The keyword all can be specified to indicate the lack of any restriction.

-S, --serial

Rather an a memdev id number, interpret the <memdev> argument(s) as a list of serial numbers.

-d, --decoder

Specify the decoder to free. The CXL specification mandates that DPA must be released in the reverse order it was allocated. See cxl-reserve-dpa(1)

-t, --type

Constrain the search for "last allocated decoder" to decoders targeting the given partition.

-f, --force

The kernel enforces CXL DPA ordering constraints on deallocation events, and the tool anticipates those and fails operations that are expected to fail without sending them to the kernel. For test purposes, continue to attempt "expected to fail" operations to exercise the driver.

-v

Turn on verbose debug messages in the library (if libcxl was built with logging and debug enabled).

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cxl-reserve-dpa(1)

2023-02-24 cxl